1. Field of the Invention
The present invention relates to an ion implanter, a beam energy measuring device, and a method of measuring beam energy.
2. Description of the Related Art
An ion implanter is provided with a device for measuring energy of an ion beam in some cases. For example, an energy measuring device measures time-of-flight of an ion at a predetermined distance, derives a speed of the ion from the distance and the measured time-of-flight, and calculates energy of the ion with use of the speed. Also, another measuring device measures energy of an ion beam from a characteristic X-ray generated when the ion beam is bombarded to a target.
Each of the above measuring devices additionally requires a dedicated configuration for energy measurement. For example, in the case of measuring time-of-flight of the ion, two sensors arranged away from each other at a predetermined distance are used. The respective sensors detect passage of the ion, and a time difference thereof is regarded as time-of-flight of the ion. Also, in the case of detecting the characteristic X-ray, a dedicated target for generating the characteristic X-ray and an X-ray detector are required. In general, addition of a new configuration to the ion implanter may cause an increase in manufacturing cost of the ion implanter.